President Donald Trump’s tweeting habits are lifting oil prices, and the U.S. leader should stop posting on social media to alleviate the spike in prices, according to one Iranian official.

“The Trump administration is pushing politics into the OPEC (Organization of Petroleum Exporting Countries), and is aiming at spreading the members and securing their own interests by getting lower prices and so forth,” Hossein Kazempour, Iran’s OPEC representative, told CNBC’s Steve Sedgwick at the Joint Ministerial Monitoring Committee (JMMC) in Algiers on Sunday.

OPEC, along with a group of Russia-led producers, put a cap on output in January 2017 in response to a supply glut and a sustained rout in oil prices that bankrupted U.S. energy firms and escalated unrest in exporting countries.

Trump has criticized the producer cartel several times over what he claims is the deliberate inflation of oil prices. The U.S. president has called it a “monopoly” and urged it to “get prices down now.” OPEC disputes Trump’s claims, arguing that its primary objective is to balance and stabilize the market.

“I think what they are doing actually is (leading to) higher prices because the fundamentals even do not warrant this level of prices,” Kazempour said.

“If they kept quiet, the prices would be cheaper, I am confident about that,” he added. “I am telling him (Trump), keep quiet, do not do any tweets, and then you will be better off in the prices.”

OPEC has come under pressure to raise output amid a steep downturn in supply among some of its biggest exporters.